... The CRIPTO/ FRL-1/CRYPTIC (CFC) domain of human Cripto Functional and structural insights through disulfide structure analysis Susan F. Foley, Herman W. T. van Vlijmen, Raymond E. Boynton, Heather ... Young and Dingyi WenBiogen, Inc., Cambridge Center, Cambridge, MA, USA The disulfide structure of the CRIPTO/ FRL-1/CRYPTIC (CFC) domain of human Cripto protein was determined bya combination of ... (Fig. 1) of mature human Cripto contains 12 cysteine residues, six in the EGF domain and six in the CFC domain. To test whether the CFC domain could retain its function independent of the EGF domain, ...